Current

Definition

Current is the flow of electric charge through a conductor, typically measured in amperes (A). It is driven by a voltage difference and encounters resistance within the material.

5 Must Know Facts For Your Next Test

1. The unit of current is the ampere (A), which represents one coulomb of charge passing through a point per second.
2. In a series circuit, the current is constant throughout all components because there is only one path for the charge to flow.
3. In a parallel circuit, the total current is the sum of the currents through each parallel branch.
4. Ohm's Law relates current ($I$), voltage ($V$), and resistance ($R$) with the formula $I = \frac{V}{R}$.
5. Measuring devices like ammeters are used to measure current, and they must be connected in series with the circuit.

Review Questions

• What happens to the total current in a parallel circuit when additional branches are added?
• How does Ohm's Law relate voltage, current, and resistance?
• Why must an ammeter be connected in series to measure current?

Related terms

Voltage:

The electric potential difference between two points, measured in volts (V).

Resistance:

The opposition to the flow of electric current, measured in ohms (Ω).

Ohm's Law:

$V = IR$, which describes the relationship between voltage (V), current (I), and resistance (R).